// SPDX-License-Identifier: GPL-2.0-or-later /* * atxp1.c - kernel module for setting CPU VID and general purpose * I/Os using the Attansic ATXP1 chip. * * The ATXP1 can reside on I2C addresses 0x37 or 0x4e. The chip is * not auto-detected by the driver and must be instantiated explicitly. * See Documentation/i2c/instantiating-devices.rst for more information. */ #include <linux/kernel.h> #include <linux/init.h> #include <linux/module.h> #include <linux/jiffies.h> #include <linux/i2c.h> #include <linux/hwmon.h> #include <linux/hwmon-vid.h> #include <linux/err.h> #include <linux/mutex.h> #include <linux/sysfs.h> #include <linux/slab.h> MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("System voltages control via Attansic ATXP1"); MODULE_VERSION("0.6.3"); MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>"); #define ATXP1_VID 0x00 #define ATXP1_CVID 0x01 #define ATXP1_GPIO1 0x06 #define ATXP1_GPIO2 0x0a #define ATXP1_VIDENA 0x20 #define ATXP1_VIDMASK 0x1f #define ATXP1_GPIO1MASK 0x0f struct atxp1_data { struct i2c_client *client; struct mutex update_lock; unsigned long last_updated; u8 valid; struct { u8 vid; /* VID output register */ u8 cpu_vid; /* VID input from CPU */ u8 gpio1; /* General purpose I/O register 1 */ u8 gpio2; /* General purpose I/O register 2 */ } reg; u8 vrm; /* Detected CPU VRM */ }; static struct atxp1_data *atxp1_update_device(struct device *dev) { struct atxp1_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; mutex_lock(&data->update_lock); if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { /* Update local register data */ data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID); data->reg.cpu_vid = i2c_smbus_read_byte_data(client, ATXP1_CVID); data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1); data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2); data->valid = 1; } mutex_unlock(&data->update_lock); return data; } /* sys file functions for cpu0_vid */ static ssize_t cpu0_vid_show(struct device *dev, struct device_attribute *attr, char *buf) { int size; struct atxp1_data *data; data = atxp1_update_device(dev); size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK, data->vrm)); return size; } static ssize_t cpu0_vid_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct atxp1_data *data = atxp1_update_device(dev); struct i2c_client *client = data->client; int vid, cvid; unsigned long vcore; int err; err = kstrtoul(buf, 10, &vcore); if (err) return err; vcore /= 25; vcore *= 25; /* Calculate VID */ vid = vid_to_reg(vcore, data->vrm); if (vid < 0) { dev_err(dev, "VID calculation failed.\n"); return vid; } /* * If output enabled, use control register value. * Otherwise original CPU VID */ if (data->reg.vid & ATXP1_VIDENA) cvid = data->reg.vid & ATXP1_VIDMASK; else cvid = data->reg.cpu_vid; /* Nothing changed, aborting */ if (vid == cvid) return count; dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid); /* Write every 25 mV step to increase stability */ if (cvid > vid) { for (; cvid >= vid; cvid--) i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA); } else { for (; cvid <= vid; cvid++) i2c_smbus_write_byte_data(client, ATXP1_VID, cvid | ATXP1_VIDENA); } data->valid = 0; return count; } /* * CPU core reference voltage * unit: millivolt */ static DEVICE_ATTR_RW(cpu0_vid); /* sys file functions for GPIO1 */ static ssize_t gpio1_show(struct device *dev, struct device_attribute *attr, char *buf) { int size; struct atxp1_data *data; data = atxp1_update_device(dev); size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK); return size; } static ssize_t gpio1_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct atxp1_data *data = atxp1_update_device(dev); struct i2c_client *client = data->client; unsigned long value; int err; err = kstrtoul(buf, 16, &value); if (err) return err; value &= ATXP1_GPIO1MASK; if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) { dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value); data->valid = 0; } return count; } /* * GPIO1 data register * unit: Four bit as hex (e.g. 0x0f) */ static DEVICE_ATTR_RW(gpio1); /* sys file functions for GPIO2 */ static ssize_t gpio2_show(struct device *dev, struct device_attribute *attr, char *buf) { int size; struct atxp1_data *data; data = atxp1_update_device(dev); size = sprintf(buf, "0x%02x\n", data->reg.gpio2); return size; } static ssize_t gpio2_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct atxp1_data *data = atxp1_update_device(dev); struct i2c_client *client = data->client; unsigned long value; int err; err = kstrtoul(buf, 16, &value); if (err) return err; value &= 0xff; if (value != data->reg.gpio2) { dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value); i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value); data->valid = 0; } return count; } /* * GPIO2 data register * unit: Eight bit as hex (e.g. 0xff) */ static DEVICE_ATTR_RW(gpio2); static struct attribute *atxp1_attrs[] = { &dev_attr_gpio1.attr, &dev_attr_gpio2.attr, &dev_attr_cpu0_vid.attr, NULL }; ATTRIBUTE_GROUPS(atxp1); static int atxp1_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; struct atxp1_data *data; struct device *hwmon_dev; data = devm_kzalloc(dev, sizeof(struct atxp1_data), GFP_KERNEL); if (!data) return -ENOMEM; /* Get VRM */ data->vrm = vid_which_vrm(); if (data->vrm != 90 && data->vrm != 91) { dev_err(dev, "atxp1: Not supporting VRM %d.%d\n", data->vrm / 10, data->vrm % 10); return -ENODEV; } data->client = client; mutex_init(&data->update_lock); hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, data, atxp1_groups); if (IS_ERR(hwmon_dev)) return PTR_ERR(hwmon_dev); dev_info(dev, "Using VRM: %d.%d\n", data->vrm / 10, data->vrm % 10); return 0; }; static const struct i2c_device_id atxp1_id[] = { { "atxp1", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, atxp1_id); static struct i2c_driver atxp1_driver = { .class = I2C_CLASS_HWMON, .driver = { .name = "atxp1", }, .probe = atxp1_probe, .id_table = atxp1_id, }; module_i2c_driver(atxp1_driver);